1. Field of the Invention
The present invention relates to a dishwasher, and more particularly, to an apparatus for controlling a washing flow of a dishwasher that can perform an upper washing, a lower washing, an alternate washing of upper and lower sides, and a concurrent washing of upper and lower sides.
2. Description of the Related Art
In general, a dishwasher is a machine, which washes food remnants adhered to dishes by spraying washing water supplied by a feed pump onto the dishes at a high pressure.
In a method of washing dishes using such a dishwasher, dishes to be washed are loaded in a washing room, washing water is fed to a selected portion of the washing room, heat and pump are operated to heat the fed washing water and to circulate the heated washing water to the pump, the heated and circulated washing water is sprayed on the dishes, thereby separating food remnants adhered to the dishes and washing the dishes.
Also, the dishwashers are classified into single-stage dishwashers and two-stages dishwashers according to the number of a rack employed for washing.
The single-stage dishwashers and the two-stage dishwashers have a difference in the number of the rack, water flow passage structure, but they basically operate using the same operational principle.
In the two-stage dishwashers which perform washing by spraying washing water on dishes through a water flow passage of an upper stage and a water flow passage of a lower stage, researches to save water amount, washing time and washing energy have been actively performed.
FIGS. 1 through 4 illustrate structures of a dishwasher for alternate washing of an upper side and a lower side.
Referring to FIGS. 1 through 4, the dishwasher includes: an inner panel 10 designed to accommodate and drain water, a sump 11 disposed at a lower side of the inner panel 10; upper and lower racks 20 and 30 installed to load dishes 1 inside the inner panel 10; upper and lower nozzle arms 21 and 31 disposed adjacent to the racks 20 and 30, for spraying water; a cleaning filter 12 installed in the sump 11, for filtering accommodated washing water; a drain pump 13 and a drain tube 14 disposed at a lower side of the sump 11, for draining washing water; a water current control pump 40 for selectively circulating the water filtered by the cleaning filter 12 to an upper part and a lower part of the inner panel 10; and upper and lower water flow passages 51 and 52 for inducing the filtered water discharged by the water current control pump 40 toward the upper nozzle arm 21 or the lower nozzle arm 41.
As shown in FIGS. 3 and 4, the water current control pump 40 includes a case 41 communicating with a lower portion of the sump 11, and having an inlet 48, and upper and lower discharge holes 42 and 43, a rotational wheel 44 installed in the case 41, and a water current switching valve 45 hinge-coupled to an inner wall of the case 41 between the upper discharge hole 42 and the lower discharge hole 43, having a front end placed adjacent to an outer circumference of the rotational wheel 44, for closing either of the upper and lower discharge holes 42 and 43 by water current formed according to variation in the rotational direction of the rotational wheel 44.
The water current switching valve 45 includes two shield plates 47 integrally formed in a V shape with a predetermined angle therebetween, and a hinge shaft 46 coupled to a junction portion of the two shield plates 47.
Also, the water current control pump 40 rotates forward or backward (i.e., clockwise or counterclockwise) at a constant period to supply washing water to the upper rack and the lower rack 20 and 30 alternatively, so that washing is performed at a maximum capacitance of the pump 40 and energy consumption is minimized.
Next, operation of the related art dishwasher for alternate washing of an upper side and a lower side will be described with reference to the accompanying drawings.
FIGS. 1 and 3 illustrate an operational state of the related art dishwasher for alternate washing of an upper side and a lower side, and FIGS. 2 and 4 are sectional views of a water current control pump 40 employed in the related art dishwasher for alternate washing of an upper side and a lower side.
Specifically, FIG. 1 shows that washing water is sprayed only on the lower lack 30 to perform the alternate lower washing, and FIG. 2 shows that the rotational wheel 44 rotates counterclockwise such that washing water may be sprayed only on the lower rack 30. Also, FIG. 3 shows that washing water is sprayed only toward the upper lack 20 for a predetermined time to perform the alternate lower washing, and FIG. 4 shows that the rotational wheel 44 rotates clockwise such that washing water may be sprayed only toward the upper rack 20.
As shown in FIGS. 1 and 2, to spray washing water only toward the lower rack 30, a predetermined amount of clean water is first supplied from an outside, collected in the sump 11, and then introduced into the water current control pump 40 through the inlet 48.
At this time, the rotational wheel 44 of the water current control pump 40 rotates counterclockwise by a selective control of a controller (not shown), so that the water in the case 41 forms water current counterclockwise by a rotational force of the rotational wheel 44 and thus the shield plate 47 of the water current switching valve 45 of the water current switching valve 45 revolves clockwise about the hinge shaft 46 to close the upper discharge hole 42.
Since the two shield plates 47 of the water current switching valve 45 are fixed in the V-shape, they are pressed while the water current is in contact with inner surfaces of the shield plates 47 during their direction conversion. Finally, the inner water is forcibly drained through the lower discharge hole 43 and is supplied toward the lower rack 30 through the lower nozzle arm 31. At the same time, the water is sprayed upward toward the lower rack 30 through the lower nozzle arm 31, thereby washing the dishes 1 received in the lower rack 30.
After that, the washing water which is sprayed and then contaminated flows down along the inner panel 10, filtered through the cleaning filter 12, collected in the sump 11, again introduced into the water current control pump 40 through the inlet 48, and is again used to wash the dishes 1.
After the above operations are repeated for a predetermined time, the rotational wheel 44 of the water current control pump 40 rotates backward clockwise by a control of the controller, so that washing water is sprayed toward the upper rack 20 as shown in FIGS. 3 and 4.
That is, the water in the case 41 forms water current in the clockwise direction by the rotational force of the rotational wheel 44, thereby allowing the shield plate 47 of the water current switching valve 45 to revolve about the hinge shaft 46 counterclockwise so that the lower discharge hole 43 is closed.
Finally, inner water is forcibly drained through the upper discharge hole 42 and is supplied toward the upper nozzle arm 21 along the upper water flow passage 51. Then, the water is sprayed upward from the upper nozzle arm 21, thereby washing the dishes 1 received in the upper rack 20.
After the dishes 1 received in the upper rack 20 are washed for a predetermined time as above, the alternate lower washing is repeatedly performed. After the alternate upper and lower washing is performed several times, contaminated washing water is sucked into the drain pump 13 and then drained to an outside through the drain pipe 14, thereby completing the washing.
However, in the related art dishwasher, it is impossible to concurrently wash the dishes received in the upper rack 20 and the dishes received in the lower rack 30. Also, it is possible to selectively perform an upper washing or a lower washing, but it is impossible to perform an alternate washing of the upper and lower racks and a concurrent washing of the upper and lower racks.